Sounds like it may be your DIS pack. They aren't easy to change as it is down the back of the engine. Plenty of info on the site if you do a search. I had the same symptoms and changed plug leads first. If you have been losing water a little it could be the Heater bypass valve and that dribbles nicely onto your DIS pack.

It could be your cam cover gaskets gone. I had that problem too on same year car etc as yours. They aren't easy to get at but pull at least one lead off both banks to check. Again loads of info on the site for changing the gaskets IF that is the problem. Use only genuine VX gaskets.

Someone else will be along with suggestions for how to test to narrow it down.

Sounds like it may be your DIS pack. They aren't easy to change as it is down the back of the engine. Plenty of info on the site if you do a search. I had the same symptoms and changed plug leads first. If you have been losing water a little it could be the Heater bypass valve and that dribbles nicely onto your DIS pack.

It could be your cam cover gaskets gone. I had that problem too on same year car etc as yours. They aren't easy to get at but pull at least one lead off both banks to check. Again loads of info on the site for changing the gaskets IF that is the problem. Use only genuine VX gaskets.

Someone else will be along with suggestions for how to test to narrow it down.

feeutfo

def miss fire. No test for dis afaik. I think its a case of easiest cheapest first. Check the wells for oil first. If no oil then how old are the plugs? 40k life i think, any black lines or tracks on the insulators. If they are ok and not due then would suggest dis pac esp if its been sprayed with water from a leaking hbv, screen seal or scuttle dripping. But its a gamble that the leads are not to blame, how do they look are they genuine, any splits in the rubber boots?

You may not have seen water loss from the heater bypass valve as it is conveniently tucked away high up at the back of the engine under the scuttle. You may just have been topping up the header tank from time to time.

Have a search on this site for how to change a DIS Pack. It is fiddly but not horribly difficult. You need to get the old one off to see which one you need to buy. From memory mine could have been one of two types.

I have not needed to top up my cooling system water for over a year, and negligible amount over almost 4 years. It is at normal level now. Maybe that suggests I'm lucky in avoiding a leaking heater bypass valve .. and maybe not the Dis Pack if it has escaped a hot shower?

Perhaps I should try to check the plugs and HT leads first? Could someone offer guidance please .. see my post above.

« Last Edit: 14 March 2009, 12:09:13 by 2am »

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feeutfo

if there is oil in the plug wells(or mine shafts) its very likely you wont notice the oil loss on the dip stick. Only way is to look, which you will when you change the plugs obviously. Pass side is the difficult side and involves removing/pulling to one side the cable tray, it aint that hard tho. Blow off any crap to stop it falling down the well and into the cylinder when the plugs come out. Inspect the plug leads and caps for any damage while your there. Look for any black lines on the white bit of the plugs and any white/grey residue on the rubber thats left when the spark escapes. Some say any spark escape can be seen at night or when dark, hold the bonnet down and look through the gap. You never know.

Start with the spark plug end and if all is well then you need to inspect the dis pac and that end of the leads. See how you go, hopefully its just the plugs and you wont have to look any further. Hth

Checked in the dark .. I cannot see any sparking around plugs or HT leads.

BUT ..

I was pressing down on each plug cap to ensure good connection. Just found something which may be part of my problem .. one spark plug may be loose.

There is a rattling sound when I press on the plug cap .. this is the same first plug that a friend tried to remove to change plugs, but he gave up because of accessibility problems down those awful "mineshafts". Problems with his plug socket reaching down there. But it looks like he did loosen that plug without realising. †

Do you think this could be the cause of the juddering and lumpy running with poor fuel consumption?

« Last Edit: 14 March 2009, 23:57:23 by 2am »

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feeutfo

Right, had a look at this for Mr 2am today and must say i am a little bemused. It was running a little lumpy when we drove it as he says. It also feels strangled and vibey. Changed the plugs, and found some oil in the wells, but nothing major, it was not as high in the well so as to reach the hight of the rubber boots on the plug caps for instance.

Plugs changed and it does sound like a subaru impreza, but the engine does not leap around in the engine bay like my old car did when one cylinder went down due to a split rubber on the plug cap. compared to that its quite smooth. Pulled a couple of plug leads while it was running, ouch, and this made little difference to the rough running. 1 and 5 barely made any dirrerence when pulled, but 3 made a slight difference.

The plug cap on cylinder 6 had a major portion of rubber missing, assuming 1 5 and 6 aint working why isnt the engine leaping around like a nutter??

Took the scuttle off to peak at the dis pac, and with both feet off the floor i could see down onto it. No visible sign of damage cracks or splitting that i can see without removing it.

also the vac system aint right, not a peep from either multi rams and there is a leak from a small pipe the back, taped that up, with a busted elbow connector on the vac tank on the inlet trumpets.

personally, if it was mine i would change the leeds, and fix the the vac system, although i have little experience of that, and go from there.

Just want to run it by you lot, and see what you think, opinions please ladys and gents. TA

ps some other monkeys have been at this car, i will leave that Mr 2amto discuss, perhaps on another thread to save confussion, we just need to sort this out for him for now, he really needs a reliable car.

Just back from hospital .. long day .. exhausted, so will post more tomorrow.

Many thanks, Chris, for having a look at my 97R 2.5 Elite saloon today.

Unfortunately changing the plugs has made no difference to the juddering lumpiness (most noticeable as soon as the auto box changes into top gear at 2000rpm at 50mph) and the poor mpg (typically high teens and just over 20mpg on a run) even with my gentle driving style.

Something has happened to change it suddenly (after the MOT) from the former smooth velvet V6 doing 28-35mpg to the more sluggish, less responsive and sometimes juddering fuel-hungry car of today. Paperclip test shows no fault codes.

If the SAI hoses have failed and the rear silencer has shed packing material are you sure there's no blockage in the exhaust system?

Might be worth checking that the ignition leads all go to the right terminal posts on the DIS pack if someone has attempted a plug change. I'd be inclined to treat it to a new set of leads if they have started to deteriorate. It's only a matter of time before they let you down but worth doing the cam cover gaskets if there is leakage, otherwise the new leads will go the same way.

I would also repair or at least block the vacuum leaks. You won't have a lot of air leaking into the system but might as well eliminate that as a cause.

Chrisgixer checked and photographed the exhaust yesterday. There seems to be good pressure at the tail pipe. It is intact externally and does not seem to be blocked. He shone a torch right through inside the rear box, which has shed its innerds, but otherwise seems ok.

He changed all the spark plugs but sadly there was no improvement. Worryingly he found an apparently clean-cut chunk of rubber from the plug cap of pot 6 .. see his photo posted last night. MOT repairs Sabotage?

I have previously made brief reference to this. I will post a separate new thread about my concerns from my recent MOT and repairs, which was immediately before my car problems started.

Could someone please explain the car's vacuum system, how critical or sensitive it is, and what the "multi-rams" do.

And Chris, could you please let me have contact details for the HT leads.

not smooth on tick over as it should be enginge vibtrating from side to sideif i held it in gears (mines auto) it seemed to smooth out a bit as you got higher up the rev range and the faster i went it seemed to get better but as i slowed down i could feel it was lumpy stillvery rotten egg smell from the exhaust on 2-3000 revs changed plugs made no differencechanged leads made no differencesworetook of dis packfound a spilt a half way round the bottom and could see rusty metal inside bought new dis pack from ebayperfect loverly and smooth againhope some of this helpsand yes i know i rabbit on

I'll second that. My same car as you developed the same symptoms. It seemed fine pootling around but on the open road when it got to about 50 and changed into top then along came the juddering - particularly on a light throttle. Change down and press accelerator gave more power and masked the misfire a bit.

feeutfo

the Exhaust back box has nothing in it. The entry pipe can clearly be seen when looking in the exit pipe with a torch. Baffle edges and rust clearly visible. But the baffle edges seemed at odd angles. Arvin meritor stickers no the back box and centre sections, so not gm from cat back. If the rear box has fallen apart then is it possible the centre section has done the same? Trouble is from what i saw in the back box, it left me with a mental image of somebody ramming a metal bar up the tail pipe.I think its worth further investigation at the very least. Something is not right with all this.

Ill leave that for another thread. Mean time the poor running, i can not understand personally why the engine is not leaping about? The dis looked ok from the top but thats no proof the under side is the same, 2am has had the car 4 years so dont think anybody has changed the leads.

Chris, Thanks for the text with contact details for HT leads and Dis Pack. I will follow that up tomorrow.

You say I also need "the vac tank on the intakes" .. please explain so that I understand what I am asking for.

I did not get a photo text. Could you please post on here .. mine is just a mobile phone, without photo facility.

Quote

But the baffle edges seemed at odd angles .. Trouble is from what i saw in the back box, it left me with a mental image of somebody ramming a metal bar up the tail pipe.I think its worth further investigation at the very least. Something is not right with all this.

That REALLY worries me .. and it reinforces my fears about that MOT garage after I queried their charges for "repairs". My Omega was a velvet smooth beauty before that MOT .. these problems of juddering running, poor MPG, and the exhaust spewing its contents, they ALL started on the first journey after I collected the "repaired" car from that MOT garage.

Add to that the other things you found yesterday .. the clean-cut chunk of rubber from the plug cap .. and the botched shock they fitted on one side, fudging the self-levelling suspension .. and it adds up to VERY GREAT CONCERN.

HT leads are arranged in pairs on the DIS pack. Can't visualise the numbering sequence off hand, but if someone with a spare DIS pack can take a look to see if 1and 5 are a pair then I think you've found your problem. Use a 1999 model year DIS pack for best results. There won't be any obvious signs of failure as the fault occurs internally (usually insulation breakdown).

Your HT leads look shot and it would be well worth replacing them. Also check to see if you've got platinum tipped plugs. These place a huge strain on the HT system and I would recommend using only copper cored NGK (BKR6EK) or Vauxhall's own brand plugs in this engine.

Please explain your comments about the HT leads. Are you wondering if the plugs #1 and #5 have been switched round?

The coil pack contains 3 separate coils which fire 2 cylinders each, spearated by 360 degrees of crank rotation. Normally, one of these coils will fail before the others so if you observed cylinders 1 and 4 missing, for example, it would be clear that the corresponding coil had failed.

feeutfo

As said on Sunday, if it was me, i would put a complaint in to Vosa. Or at least contacat them re the complaints procedure. If your an AA member i would be in touch with them for an independent report. Thing is, most issues will be hard to prove, but the rear shock is fairly cast iron proof imho, if you have the receipt for the shock and labour for fitting it.

For info, the car has a Monroe shock fitted, it is not self levelling. The air pipe has been cable tied up to the fuel filter and left to vent freely. The other is standard self level and working fine all be itwith the air pipe stretched tight with no slack.

Result is about 2.5 inches difference in ride hight between the rear wheels. The car has presumably passed the MOT in this state. When 2am followed me to my house, i could see that the car was not level from my rear view mirror.

In all honesty i was more concerned with the rough running when 2am arrived, having seen the shock and the rear box I am very suspicious. 2am also sounds like he was over charged for the Brakes fitted.Will post all pics taken in a mo if the lapy ever fires up.

feeutfo

Please explain your comments about the HT leads. Are you wondering if the plugs #1 and #5 have been switched round?

The coil pack contains 3 separate coils which fire 2 cylinders each, spearated by 360 degrees of crank rotation. Normally, one of these coils will fail before the others so if you observed cylinders 1 and 4 missing, for example, it would be clear that the corresponding coil had failed.

1 and 5 don't share a coil though. :-/

I think exchanging the leads and coil pack is a good plan.

Kevin

might explane why the engine is not leeping around. If an opposing pair of cylinders has gone down the firing order will still be balanced, a v4 for instance. Or a v2 perhaps.

Three more things I would advise to check:-Cambelt settings Set the crank in proper position (mark on pulley with mark on the oil pump), undo 2 bolts on the cover and check if marks on cam shaft pulleys are lined with cover marks. -System voltage (one car was going crazy when hot Ė it was charging 14-17V)-EGR valve (undo and clean it)

Just back from buying car parts from breaker .. Steve at OmegaSpareParts .. friendly chap. I now have ..

- HT Lead set- Dis Pack- Vacuum System Tank + elbows

Thanks guys for other suggestions. I will highlight those to Chrisgixer who is helping me.

I need to move forward cautiously .. circumstances mean I need to minimise costs .. so first priority is to ensure that the juddering and fuel consumption problems have been resolved before incurring further significant costs .. but other checks and maintenance also needs to be done, perhaps at the same time.

Please explain your comments about the HT leads. Are you wondering if the plugs #1 and #5 have been switched round?

The coil pack contains 3 separate coils which fire 2 cylinders each, spearated by 360 degrees of crank rotation. Normally, one of these coils will fail before the others so if you observed cylinders 1 and 4 missing, for example, it would be clear that the corresponding coil had failed.

Let me make sure I understand this. Your electrical testing procedure is to test the EXISTING Dis Pack in situ to see if it is functioning properly? And if it is working within those electrical ranges then it does not need to be replaced? Will that be conclusive proof for all rev speeds? Please confirm.

Does this require any particular type of AVO meter? I know Chris has lots of tools but I will check after you confirm what is needed.

I have bought a replacement Dis Pack yesterday - but your suggestion of testing is very welcome because it might mean the replacement may not be needed.

Yes, you can check the DIS pack when itís out of the car. It cannot be connected. You can check the resistance so this should show any irregularities like rev related (poor voltage conversion, short circuit). It might not show any problems heat related as when cold resistance can be OK. You can use the cheapest reader http://irma.pl/photos/article/miernik_elektryczny.jpg like this one Did you managed to check any engine fault codes using code reader (not the paperclip test)? Itís also good to check all information about the engine Ė MAF sensor values, O2 sensors, engine temp etc. What about spark plugs Ė do they looks the same or are there any different color? Ė you can check old ones.

Let me make sure I understand this. Your electrical testing procedure is to test the EXISTING Dis Pack in situ to see if it is functioning properly? And if it is working within those electrical ranges then it does not need to be replaced? Will that be conclusive proof for all rev speeds? Please confirm. Yes, but it needs to be disconected. This way you can check if any of the coils is faulty. If DIS pack problem is heat related, I'm affraid it will not show anything in low temp.

Does this require any particular type of AVO meter? I know Chris has lots of tools but I will check after you confirm what is needed. Standard one, with proper resistance range is fine.

I have bought a replacement Dis Pack yesterday - but your suggestion of testing is very welcome because it might mean the replacement may not be needed.

I try not to replace parts if I'm not quite sure they're broken. Sometime's you just cant tell and have to replace it

Did you manage to check any engine fault codes using code reader (not the paperclip test)? Itís also good to check all information about the engine Ė MAF sensor values, O2 sensors, engine temp etc. What about spark plugs Ė do they look the same or are there any different colour? Ė you can check old ones.

I did the Paperclip test several times .. no faults shown (just 12 repeating). Please explain what is a "code reader" and what needs to be done.

All the spark plugs were replaced last Sunday using Bosch 520 FR91X Super 4 plugs, but it made no difference. The old ones seemed mostly OK .. no black arc scorch lines on insulators .. but a small amount of oil on outside, though Chris said not deep in wells.

Does it sound like I can avoid changing the rocker cover gaskets for now? I would prefer to know that the juddering has been resolved and the fuel economy has been restored before I incur further costs.